In fuel pumps of the piston-type, the pistons may be connected to a swash plate assembly, so that oscillatory motion of the swash plate assembly and resultant reciprocal motion of the pistons causes fuel to be pumped at a relatively high pressure to the combustion chambers or cylinders of an internal combustion engine. Although it is essential to prevent the escape of fuel, in the past sealing has been a problem.
In accordance with the present invention, a bellows surrounds the pistons. The bellows is preferably in the form of a thin-walled, flexible, cylindrical tube preferably made of metal and having a sinuous side wall. One end of the bellows is connected to the swash plate assembly and the other end is connected to a base or barrel having cylinder bores in which the pistons reciprocate. As a result, the bellows provides a closed interior space surrounding the pistons and preventing the escape of fuel.
One object of this invention is to provide a piston-type fuel pump having the foregoing features and capabilities.
Another object is to provide a piston-type fuel pump employing a bellows for sealing the internal movable parts of the fuel pump.
These and other objects, features and advantages of the invention will become more apparent as the following description proceeds, especially when considered with the accompanying drawings.